#include "mystdio.h"

FILE_ *fopen_(const char *path_name, const char *mode)
{
    int flags = 0;
    int defaultMode = 0666;
    if (strcmp(mode, "r") == 0)
    {
        flags |= O_RDONLY;
    }
    else if (strcmp(mode, "w") == 0)
    {
        flags |= (O_WRONLY | O_TRUNC | O_CREAT);
    }
    else if (strcmp(mode, "a") == 0)
    {
        flags |= (O_WRONLY | O_APPEND | O_CREAT);
    }
    else
    {
        // TODO;
    }

    int fd = 0;
    if (flags & O_RDONLY)
        fd = open(path_name, flags);
    else
        fd = open(path_name, flags, defaultMode);

    if (fd < 0)
    {
        const char *err = strerror(errno);
        write(2, err, strerror(err));
        return NULL;
    }
    FILE_ *fp = (FILE_ *)malloc(sizeof(FILE_));
    assert(fp);

    fp->flags = SYNC_LINE; // 默认行刷新
    fp->fileno = fd;
    fp->cap = SIZE;
    fp->size = 0;
    memset(fp->buffer, 0, SIZE);
    fp->buffer[0] = 0;

    return fp;
}

void fwrite_(const void *ptr, int num, FILE_ *fp)
{
    // 1.写入缓冲区
    memcpy(fp->buffer + fp->size, ptr, num);
    fp->size += num;

    // 2.是否刷新
    if (fp->flags & SYNC_NOW)
    {
        write(fp->fileno, fp->buffer, fp->size);
        fp->size = 0; // 清空缓冲区，惰性释放
    }
    else if (fp->flags & SYNC_FULL)
    {
        if (fp->size == fp->cap)
        {
            write(fp->fileno, fp->buffer, fp->size);
            fp->size = 0;
        }
    }
    else if (fp->flags & SYNC_LINE)
    {
        if (fp->buffer[fp->size - 1] == '\n')
        {
            write(fp->fileno, fp->buffer, fp->size);
            fp->size = 0;
        }
    }
    else
    {
    }
}

void fflush_(FILE_ *fp)
{
    if (fp->size > 0)
        write(fp->fileno, fp->buffer, fp->size);
    fp->size = 0;
}

void fclose_(FILE_ *fp)
{
    fflush_(fp);
    printf("\n");
    close(fp->fileno);
}